Resumen

The Neotropical river otter Lontra longicaudis is a top predator in many South and Central American aquatic freshwater systems. Its current category in the International Union for Conservation of Nature is "data deficient," which makes it imperative to determine the appropriate conservation status. We applied species distribution models to build a map of habitat suitabilities, and to identify possible anthropogenic factors that affect the presence of L. longicaudis in the Lower Delta of the Paraná River in the Southern Cone of South America. Presence/absence of L. longicaudis was obtained using 3 methodologies (sign surveys, camera traps, and interviews) and 15 environmental predictors. Habitat suitability was higher in areas with polders built for forestry, and lower in areas with human settlements and boat traffic. At present, geographic isolation and control of access on private land and reserves appear to be effective at protecting wildlife in the Paraná Delta. Our study demonstrates that species distribution models can be used for rapidly evaluating potential threats to wildlife.